152 research outputs found
Steam-Induced Coarsening of Single-Unit-Cell MFI Zeolite Nanosheets and Its Effect on External Surface Brønsted Acid Catalysis.
Commonly used methods to assess crystallinity, micro-/mesoporosity, Brønsted acid site density and distribution (in micro- vs. mesopores), and catalytic activity suggest nearly invariant structure and function for aluminosilicate zeolite MFI two-dimensional nanosheets before and after superheated steam treatment. Yet, pronounced reaction rate decrease for benzyl alcohol alkylation with mesitylene, a reaction that cannot take place in the zeolite micropores, is observed. Transmission electron microscopy images reveal pronounced changes in nanosheet thickness, aspect ratio and roughness indicating that nanosheet coarsening and the associated changes in the external (mesoporous) surface structure are responsible for the changes in the external surface catalytic activity. Superheated steam treatment of hierarchical zeolites can be used to alter nanosheet morphology and regulate external surface catalytic activity while preserving micro- and mesoporosity, and micropore reaction rates
Zakah compliance behavior among entrepreneurs: economic factors approach
Purpose – As one of the constituted main pillars of Islam, Zakah compliance (ZC) is mandated upon
Muslims from all studies of life. Taking the disappointingly low compliance level in developing countries, including Yemen, as its backdrop, the purpose of this study is to investigate ZC behavior among entrepreneurs, drawing on the economic approach perspective. Design/methodology/approach – The study adopted a cross-sectional design based on a survey of
entrepreneurs in Yemen. It used primary data collected via self-administered questionnaires, involving a sample of 500 participants. A variance-based structural modeling equation-partial least squares were used to measure the instruments and assess the hypothesized relationships. Findings – The findings affirmed the suitability of the economic factors approaches in the context of ZC in a developing country. Specifically, the study demonstrated that Zakah law complexity has a significant negative influence on ZC of entrepreneurs. It also found a significant positive relationship between religiosity and ZC among the study sample, whereas the study revealed that law enforcement has no influence on compliance behavior.Practical implications – Policies and programs focused on Zakah laws and regulations could be formulated to make them less complex and simpler for acceptable levels of ZC. The result is further relevant to
policymakers in Muslim communities to strengthen the religious faith of Zakah payers toward compliance with one of the fundamental religious obligations such as Zakah.Originality/value – This study enriches the limited previous studies on actual ZC from the perspective of developing communities, especially Yemen. Most importantly, the value was added to the limited literature
internationally from an economic aspect
Self-Pillared, Single-Unit-Cell Sn-MFI Zeolite Nanosheets and Their Use for Glucose and Lactose Isomerization
Single-unit-cell Sn-MFI, with the detectable Sn uniformly distributed and exclusively located at framework sites, is reported for the first time. The direct, single-step, synthesis is based on repetitive branching caused by rotational intergrowths of single-unit-cell lamellae. The self-pillared, meso- and microporous zeolite is an active and selective catalyst for sugar isomerization. High yields for the conversion of glucose into fructose and lactose to lactulose are demonstrated
Pillared Sn-MWW Prepared by a Solid-State-Exchange Method and its Use as a Lewis Acid Catalyst
Pillared Sn-MWW (Sn-MWW(SP)-SSE) was prepared through a solid-state-exchange (SSE) route. The pillared structure was inherited from pillared B-MWW, and Sn was inserted in the framework by boron leaching and solid-state-exchange with tin tetrachloride pentahydrate. The Sn-MWW(SP)-SSE with framework Sn sites exhibits Lewis acidity and good catalytic performance for the Baeyer–Villiger oxidation, and mono- and disaccharide isomerizations
Association Between Hemoglobin A1C and the Severity of Acute Ischemic Stroke in Sudanese Patients in Omdurman Military Hospital
Background: Hemoglobin A1C (HbA1c) levels are known to be linked to a higher risk of stroke. However, no research data is available on the impact of HbA1C on the severity of acute ischemic stroke in Sudan. Methods: This study is a descriptive, cross-sectional hospital-based study of 40 cases of acute ischemic stroke. Ischemic stroke was confirmed using computed tomography (CT) scan at admission; all subjects’ blood HbA1C levels were also measured. Participants were divided into two subgroups based on HbA1C at admission, good glycemic control (GGC) (<7 HbA1C) and poor glycemic control (PGC) (>7 HbA1C), and neurological impairment was assessed using the National Institutes of Health Stroke Scale (NIHSS). Results: The age distribution of the participants was 45-85 years, with an average age of 63.5±9.2 years with the highest frequency (67.5%) in the age group of 55-75 years. PGC had a statistically significant high HbA1C value of 8.9±1.3 (P=0.000), when compared to GGC subgroups 5.1±0. The association between stroke severity and HbA1C levels on admission in this study was statistically significant (P value=0.005), on admission (78.6%) PGC had moderate to severe stroke (> 18.8 NIHSS) versus (33.3%) that of the GGC (>10.4NIHSS). The frequency of elevated HbA1C levels in patients with acute ischemic stroke was 70% in this study. Conclusion: PGC was shown to be linked to the occurrence of stroke and to its severity
Experiences of frontline nurses with adverse medical events in a regional referral hospital in northern Ghana:a cross-sectional study
BackgroundAdverse medical events (AMEs) are threats to delivery of quality healthcare services, particularly in resource-poor settings such as Ghana. In sub-Saharan Africa, 30% of deaths are attributed to AMEs and a significant proportion of these events are not reported. This study explored personal experiences of nurses with AMEs and the constraints to reporting them.MethodsThis is a descriptive cross-sectional study among professional (n = 133) and auxiliary (n = 88) nurses in a regional referral hospital in northern Ghana. A test for differences in experiences of professional and auxiliary nurses was done using Wilcoxon Mann-Whitney test. Ordered logistic regression analysis (proportional odds ratio models) and probit regression were used to ascertain the determinants of staff’s knowledge on AMEs and the odds of exposure, respectively.ResultsOverall, knowledge and awareness level on AMEs was average (mean = 3.1 out of the five-point Likert scale of 1 = “Very poor” to 5 = “Excellent”). Knowledge levels among professional nurses (mean = 3.2) were relatively higher than those among auxiliary nurses (mean = 3.0), (p = 0.006). The predominant type of AME experienced was wrongful documentation (n = 144), and the least experienced type was wrong transfusion of blood and/or intravenous fluids (IVF) (n = 40). Male staff had higher odds of experiencing medical errors relative to female staff, OR = 2.39 (95% confidence interval (CI), 1.34–4.26). Inadequate logistics was the most perceived cause of AMEs. Knowledge on types of AMEs was significantly associated with gender of the respondents, OR = 1.76 (95% CI, 1.05–2.94); moreover, male staff had higher odds of knowing AME post-exposure action than female staff, OR = 1.75 (95% CI, 1.04–2.93).ConclusionKnowledge levels of nursing staff on AMEs were generally low, and even though exposures were high they were not reported. There is the need to integrate AME modules into the pre-service and in-service training curricula for nurses to enhance their knowledge on AMEs; reporting registers for AMEs should be made available in clinical sites and staff incentives given to those who report AMEs. Lastly, protocols on AMEs should form part of the quality assurance value chain for health facilities to promote compliance
Experiences of frontline nurses with adverse medical events in a regional referral hospital in northern Ghana:a cross-sectional study
BackgroundAdverse medical events (AMEs) are threats to delivery of quality healthcare services, particularly in resource-poor settings such as Ghana. In sub-Saharan Africa, 30% of deaths are attributed to AMEs and a significant proportion of these events are not reported. This study explored personal experiences of nurses with AMEs and the constraints to reporting them.MethodsThis is a descriptive cross-sectional study among professional (n = 133) and auxiliary (n = 88) nurses in a regional referral hospital in northern Ghana. A test for differences in experiences of professional and auxiliary nurses was done using Wilcoxon Mann-Whitney test. Ordered logistic regression analysis (proportional odds ratio models) and probit regression were used to ascertain the determinants of staff’s knowledge on AMEs and the odds of exposure, respectively.ResultsOverall, knowledge and awareness level on AMEs was average (mean = 3.1 out of the five-point Likert scale of 1 = “Very poor” to 5 = “Excellent”). Knowledge levels among professional nurses (mean = 3.2) were relatively higher than those among auxiliary nurses (mean = 3.0), (p = 0.006). The predominant type of AME experienced was wrongful documentation (n = 144), and the least experienced type was wrong transfusion of blood and/or intravenous fluids (IVF) (n = 40). Male staff had higher odds of experiencing medical errors relative to female staff, OR = 2.39 (95% confidence interval (CI), 1.34–4.26). Inadequate logistics was the most perceived cause of AMEs. Knowledge on types of AMEs was significantly associated with gender of the respondents, OR = 1.76 (95% CI, 1.05–2.94); moreover, male staff had higher odds of knowing AME post-exposure action than female staff, OR = 1.75 (95% CI, 1.04–2.93).ConclusionKnowledge levels of nursing staff on AMEs were generally low, and even though exposures were high they were not reported. There is the need to integrate AME modules into the pre-service and in-service training curricula for nurses to enhance their knowledge on AMEs; reporting registers for AMEs should be made available in clinical sites and staff incentives given to those who report AMEs. Lastly, protocols on AMEs should form part of the quality assurance value chain for health facilities to promote compliance
Pillared Sn-MWW Prepared by a Solid-State-Exchange Method and its Use as a Lewis Acid Catalyst
Pillared Sn-MWW (Sn-MWW(SP)-SSE) was prepared through a solid-state-exchange (SSE) route. The pillared structure was inherited from pillared B-MWW, and Sn was inserted in the framework by boron leaching and solid-state-exchange with tin tetrachloride pentahydrate. The Sn-MWW(SP)-SSE with framework Sn sites exhibits Lewis acidity and good catalytic performance for the Baeyer–Villiger oxidation, and mono- and disaccharide isomerizations
Synthesis of 2D Germanane (GeH):a New, Fast, and Facile Approach
Germanane (GeH), a germanium analogue of graphane, has recently attracted considerable interest because its remarkable combination of properties makes it an extremely suitable candidate to be used as 2D material for field effect devices, photovoltaics, and photocatalysis. Up to now, the synthesis of GeH has been conducted by substituting Ca by H in a beta-CaGe2 layered Zintl phase through topochemical deintercalation in aqueous HCl. This reaction is generally slow and takes place over 6 to 14 days. The new and facile protocol presented here allows to synthesize GeH at room temperature in a significantly shorter time (a few minutes), which renders this method highly attractive for technological applications. The GeH produced with this method is highly pure and has a band gap (E-g) close to 1.4 eV, a lower value than that reported for germanane synthesized using HCl, which is promising for incorporation of GeH in solar cells
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